Develop Reference

How to reference JFrame

I have a problem which is most likely "simple" however I can't figure it out. I am trying to reference my current JFrame so that I can dispose of it, and create a new one, thus "resetting" the program, however I and having trouble figuring out how to reference the JFrame, I have tried, super, this and getParent(), but none of the seem to work. Thanks for any / all help. ^^
Here is my code:
Main Class, just sets up the Jframe and calls the class that creates everything:
public static void main(String args[]) {
JFrame window = new JFrame();
Director director = new Director(window, args);
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setLocationRelativeTo(null);
window.pack();
window.setVisible(true);
}
}
Class the creates everything:
import java.awt.Color;
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
public class Director extends JFrame implements CollisionListener {
private BrickWall wall;
private JLabel gameTitle, gameScore, gameLives;
private JPanel controlPanel;
private JButton reset, quit;
private JRadioButton hard, normal, easy;
private int score = 6, lives = 5;
private ButtonGroup difficulty;
public Director(JFrame window, String[] args) {
window.getContentPane().add(makeGamePanel(), BorderLayout.CENTER);
window.getContentPane().add(gameControlPanel(), BorderLayout.NORTH);
}
public void collisionDetected(CollisionEvent e) {
wall.setBrick(e.getRow(), e.getColumn(), null);
}
private JComponent makeGamePanel() {
wall = new BrickWall();
wall.addCollisionListener(this);
wall.buildWall(3, 6, 1, wall.getColumns(), Color.GRAY);
return wall;
}
// Reset method I'm trying to dispose of the JFrame in.
private void reset() {
JFrame frame = new JFrame();
frame.getContentPane().add(makeGamePanel(), BorderLayout.CENTER);
frame.getContentPane().add(gameControlPanel(), BorderLayout.NORTH);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
private JComponent gameControlPanel() {
// CONTROL PANEL PANEL!
controlPanel = new JPanel();
gameTitle = new JLabel("Brickles");
gameScore = new JLabel("Score:" + " " + score);
gameLives = new JLabel("Lives:" + " " + lives);
reset = new JButton("Reset");
quit = new JButton("Quit");
hard = new JRadioButton("Hard", false);
normal = new JRadioButton("Normal", true);
easy = new JRadioButton("Easy", false);
difficulty = new ButtonGroup();
difficulty.add(hard);
difficulty.add(normal);
difficulty.add(easy);
controlPanel.setLayout(new GridLayout(4, 2));
controlPanel.add(gameTitle);
controlPanel.add(gameScore);
controlPanel.add(hard);
controlPanel.add(gameLives);
controlPanel.add(normal);
controlPanel.add(reset);
controlPanel.add(easy);
controlPanel.add(quit);
// Action Listener, where I'm caling the reset method.
reset.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
reset();
}
});
return controlPanel;
}
}

You can refer to the "outer this" from a nested class with the following syntax:
reset.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
Director.this.reset();
}
});

Yes, you can refer to the outer class by specifying it with the class name as noted in DSquare's good answer (1+ to it), but I urge you not to fling JFrame's at the user as you're program is trying to do. I recommend:
Instead of opening and closing multiple JFrames, use only one JFrame as the main application's window.
If you need helper windows, such as modal windows to get critical information that is absolutely needed, before the program can progress, use modal dialogs such as JDialogs or JOptionPanes.
If you need to swap GUI's, instead of swapping JFrames, swap "views" inside the JFrame via a CardLayout.
Gear your code towards creating these JPanel views and not JFrames as it will make your Swing GUI's much more flexible and portable.

JButton changes size

I have a JFrame, and whenever I switch from one JFrame using a JButton it starts out normally, but whenever I create a new instance of the first JFrame, the JButton is in an incorrect location and is the wrong size.
Example on startup
and when another one is created
Code:
public class Menu extends JFrame implements Runnable {
private static final long serialVersionUID = 1L;
public static int Number_of_Participants = 0;
protected JPanel window = new JPanel();
double p;
private JButton Participants;
private Rectangle rParticipants;
protected int Button_width = 240;
protected int Button_height = 48;
boolean running = false;
Thread thread;
JFrame frame = new JFrame();
public Menu() {
window.setBackground(Color.BLUE);
frame.setSize(new Dimension(800, 600));
frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
frame.getContentPane().add(window);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
Image image = null;
try {
image = ImageIO.read(new File("res/BG.jpg"));
} catch (IOException e) {
e.printStackTrace();
}
generateFiles();
drawButtons();
startMenu();
frame.repaint();
}
public void drawButtons() {
rParticipants = new Rectangle(520, 12, Button_width, Button_height);
Participants = new JButton("A");
Participants.setBounds(rParticipants);
window.add(Participants);
Participants.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
frame.dispose();
new Participant(Number_of_Participants);
}
});
}
}
Participant.java extends Menu.java
int Participant_ID;
public Participant(int Participant_ID) {
super();
this.Participant_ID = Participant_ID;
}
makes a JButton that goes back to Menu.java

As mentioned in the comment, your problem is most likely related to the call to setVisible(true). This should always be the LAST call in the constructor. Particularly, it should only be called AFTER all components have been added to the frame.
Apart from that, from the code that you posted, it seems like you want to switch through a seqence of frames, starting with a "main" menu, and then going through one frame for each "Participant". This intention could already be considered as questionable, because closing and disposing a JFrame just in order to create a new one does not seem to be very elegant. Most likely, a more elegant solution would be possible with a CardLayout : http://docs.oracle.com/javase/tutorial/uiswing/layout/card.html
However, some general hints:
Create the GUI on the Event Dispatch Thread
Don't extend JFrame. Instead, create a JFrame and fill it as needed
Don't implement Runnable with your top level class
Obey the standardJavaNamingConventions!
Don't try to do manual layouts with setBounds
This code is still not "beautiful", but at least shows how the goal of switching through several frames might be achieved, taking into account these points
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class MenuExample
{
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
#Override
public void run()
{
JPanel mainMenuPanel = new MainMenuPanel();
createAndShowFrame(mainMenuPanel);
}
});
}
static void createAndShowFrame(JPanel panel)
{
JFrame frame = new JFrame();
frame.getContentPane().add(panel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(new Dimension(800, 600));
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
static JButton createNextParticipantButton(
final JComponent container, final int nextID)
{
JButton nextParticipantButton = new JButton("New Participant");
nextParticipantButton.addActionListener(new ActionListener()
{
#Override
public void actionPerformed(ActionEvent e)
{
Window window =
SwingUtilities.getWindowAncestor(container);
window.dispose();
ParticipantPanel participantPanel =
new ParticipantPanel(nextID);
createAndShowFrame(participantPanel);
}
});
return nextParticipantButton;
}
}
class MainMenuPanel extends JPanel
{
public MainMenuPanel()
{
setBackground(Color.BLUE);
add(MenuExample.createNextParticipantButton(this, 0));
}
}
class ParticipantPanel extends JPanel
{
private final int participantID;
public ParticipantPanel(int participantID)
{
this.participantID = participantID;
add(new JLabel("Add the contents for participant "+participantID));
add(MenuExample.createNextParticipantButton(this, participantID+1));
}
}

JLabel tooltiptext not showing

I expected this to be very simple and straightforward, but tooltiptext is not showing upon hovering the mouse over. I tried printing the text and it prints correctly. Any comments what I'm doing wrong?
public class gui2 extends JFrame {
private JLabel item1;
public gui2() {
super("The title bar");
setLayout(new FlowLayout());
item1 = new JLabel("label 1");
item1.setToolTipText("This is a message");
String str = item1.getToolTipText();
System.out.println(str);
add(item1);
}
class gui {
public static void main(String[] args) {
gui2 g2 = new gui2();
g2.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
g2.setSize(400, 200);
g2.setVisible(true);
}
}
}

Your code does not compile even if you add the imports. Here is your code corrected and working :
import java.awt.FlowLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class Gui {
public static void main(String[] args) {
Window window = new Window();
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setSize(400, 200);
window.setVisible(true);
}
}
class Window extends JFrame {
private static final long serialVersionUID = 1L;
private JLabel jlabel;
public Window() {
super("The title bar");
setLayout(new FlowLayout());
jlabel = new JLabel("label 1");
jlabel.setToolTipText("This is a message");
String str = jlabel.getToolTipText();
System.out.println(str);
add(jlabel);
}
}

As mentioned by #restricteur your code does not compile.
This is due to the fact that your class gui which holds the main(..) is nested within another class, hence no static declaration of method is allowed unless the nested class is marked static. ( I simply moved/un-nested Gui out from Gui2)
Besides that your code does work, I think you are being hasty - hold the mouse over JLabel for like 3-4 seconds and you should see the ToolTip appear:
(using your code with no compilation error of course):
Suggestions on code:
1) Please watch java naming conventions i.e class names should begin with a capital letter and each new word thereafter should also i.e gui becomes Gui or GUI but I prefer the former.
2) Dont call setSize on JFrame use and= appropriate LayoutManager and call pack() on JFrame before setting it visible (but after components have been added).
3) Dont extend JFrame unnecessarily simply create an instance and use that.
4) Always create and manipulate Swing Components on Event Dispatch Thread via SwingUtilities.invokeLater(Runnable r) block.
5) Opt for setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); unless using Timers as this will allow main(..) to continue regardless if GUI is exited.
Here is code with above fixes:
import java.awt.FlowLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
class Gui2 {
private JLabel item1;
private JFrame frame;
public Gui2() {
frame = new JFrame("The title bar");
frame.setLayout(new FlowLayout());
item1 = new JLabel("label 1");
item1.setToolTipText("This is a message");
String str = item1.getToolTipText();
System.out.println(str);
frame.add(item1);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
}
class Gui {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Gui2();
}
});
}
}

IndexOutOfBounds tracking mouse with swing gui

I can't figure out why this simple program I wrote gets an IndexOutOfBounds exception when trying to update the coordinates of the mouse when the mouse leaves the tracking area (the white JPanel). I thought that the check on line 38 would take care of it. Any suggestions? Thanks!
import java.awt.*;
import javax.swing.JFrame;
public class MainFrame extends JFrame {
private static final long serialVersionUID = 1L;
Label coorLabel;
Panel coorPanel, content;
public MainFrame(String s){
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container cont = getContentPane();
coorLabel = new Label("Mouse Coordinates: ");
coorPanel = new Panel();
coorPanel.setPreferredSize(new Dimension(400,400));
coorPanel.setBackground(Color.WHITE);
/**
content = new Panel();
content.add(coorPanel, BorderLayout.PAGE_START);
content.add(coorLabel, BorderLayout.PAGE_END);
**/
cont.add(coorPanel, BorderLayout.PAGE_START);
cont.add(coorLabel, BorderLayout.PAGE_END);
pack();
setVisible(true);
}
public void updateCoor(){
if(coorPanel.getMousePosition()!=null){
coorLabel.setText("Mouse Coordinates: "+getMousePosition().x+", "+getMousePosition().y);
coorLabel.repaint();
}
}
public static void main(String[]args){
MainFrame frame = new MainFrame("Coor App");
while(true){
frame.updateCoor();
}
}
}

Take a look at Concurrency in Swing tutorial. You are completely hogging initial
thread with a while(true) loop and updating user interface outside of Event Dispatch Thread.
See Introduction to Event Listeners to get familiar with Swing event model and How to Write a Mouse-Motion Listener in particular for mouse motion listener example.

Here is what you should do:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import javax.swing.*;
public class Stack extends JFrame implements MouseMotionListener{
int x;
int y;
JPanel p = new JPanel();
JPanel detectPanel = new JPanel();
JTextField t = new JTextField(10);
JLabel l = new JLabel("Position's inside of bordered panel: ");
public Stack(){
setLayout(new BorderLayout());
t.setEditable(false);
p.add(l);
p.add(t);
detectPanel.setBorder(BorderFactory.createLineBorder(Color.BLACK));
add(p,BorderLayout.NORTH);
add(detectPanel,BorderLayout.CENTER);
detectPanel.addMouseMotionListener(this);
}
public static void main(String[] a){
SwingUtilities.invokeLater(new Runnable(){
public void run(){
Stack s = new Stack();
s.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
s.setLocationByPlatform(true);
s.setPreferredSize(new Dimension(640,480));
s.pack();
s.setVisible(true);
}
});
}
public void mouseDragged(MouseEvent e) {
}
public void mouseMoved(MouseEvent e) {
x= e.getX();
y= e.getY();
t.setText(x+", "+y);
}
}

You check to see if coorPanel.getMousePosition() is not null, but then reference (this.)getMouseLocation(); try changing that to just say getMousePosition in the check, and add a print:
if( this.getMousePosition() != null ){
System.out.println(getMousePosition());
coorLabel.setText("Mouse Coordinates: "+getMousePosition().x+", "+getMousePosition().y);
coorLabel.repaint();
}

change jlabel with method

I am writing a small program that converts files, and I wanted to have a box pop up that asks the user to please wait while the program loops through and converts all the relevant files, but I am running into a small problem. The box that pops up should have a JLabel and a JButton, while the user is "waiting" I wanted to display a message that says please wait, and a disabled "OK" JButton, and then when its finished I wanted to set the text of the JLabel to let them know that It successfully converted their files, and give them a count of how many files were converted. (I wrote a method called alert that sets the text of the label and enables the button.) The problem is That while the program is running, the box is empty, the Label and the Button are not visible, when it finishes, label appears with the final text that I want and the button appears enabled. I am not sure exactly what is going on, I tried changing the modifiers of the JLabel and JButton several times but I cant seem to get it to work correctly. Here is the code for the box that pops up, any help is greatly appricated.
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class PleaseWait extends javax.swing.JFrame{
private static final int height = 125;
private static final int width = 350;
final static JLabel converting = new JLabel("Please Wait while I convert your files");
private static JButton OK = new JButton("OK");
public PleaseWait(){
// creates the main window //
JFrame mainWindow = new JFrame();
mainWindow.setTitle("Chill For A Sec");
mainWindow.setSize(width, height);
mainWindow.setDefaultCloseOperation(DISPOSE_ON_CLOSE);
// creates the layouts//
JPanel mainLayout = new JPanel(new BorderLayout());
JPanel textLayout = new JPanel(new FlowLayout());
JPanel buttonLayout = new JPanel(new FlowLayout());
// Sets Text //
converting.setText("Please wait while I convert your files");
// disables button //
OK.setEnabled(false);
// adds to the layouts //
textLayout.add(converting);
buttonLayout.add(OK);
mainLayout.add(textLayout, BorderLayout.CENTER);
mainLayout.add(buttonLayout, BorderLayout.SOUTH);
// adds to the frame //
mainWindow.add(mainLayout);
// sets everything visible //
mainWindow.setVisible(true);
}
public static void alert(){
OK.setEnabled(true);
String total = String.valueOf(Convert.result());
converting.setText("Sucsess! " + total + " files Converted");
}
}

Okay here's the issue. You are extending the JFrame . That means your class IS a JFrame.
When you create the PleaseWait frame you don't do anything to it. This is the empty box you are seeing. You are instead creating a different JFrame in your constructor. Remove your mainWindow and instead just use this. Now all of your components will be added to your PleaseWait object. That should fix your blank box issue.

You need an application to create your frame first. This is a simple example of such application.
import javax.swing.UIManager;
import java.awt.*;
public class Application {
boolean packFrame = false;
//Construct the application
public Application() {
PleaseWait frame = new PleaseWait();
//Validate frames that have preset sizes
//Pack frames that have useful preferred size info, e.g. from their layout
if (packFrame) {
frame.pack();
}
else {
frame.validate();
}
//Center the window
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
Dimension frameSize = frame.getSize();
if (frameSize.height > screenSize.height) {
frameSize.height = screenSize.height;
}
if (frameSize.width > screenSize.width) {
frameSize.width = screenSize.width;
}
frame.setLocation((screenSize.width - frameSize.width) / 2, (screenSize.height - frameSize.height) / 2);
frame.setVisible(true);
frame.convert();
}
//Main method
public static void main(String[] args) {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
}
catch(Exception e) {
e.printStackTrace();
}
new Application();
}
}
You have to slightly modify your frame to add controls to the content pane. You can do some work after frame is created, then call alert.
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class PleaseWait extends JFrame {
private static final int height = 125;
private static final int width = 350;
final static JLabel converting = new JLabel();
private static JButton OK = new JButton("OK");
BorderLayout borderLayout1 = new BorderLayout();
JPanel contentPane;
int count;
public PleaseWait(){
contentPane = (JPanel)this.getContentPane();
contentPane.setLayout(borderLayout1);
this.setSize(new Dimension(width, height));
this.setTitle("Chill For A Sec");
this.setDefaultCloseOperation(DISPOSE_ON_CLOSE);
// creates the layouts//
JPanel mainLayout = new JPanel(new BorderLayout());
JPanel textLayout = new JPanel(new FlowLayout());
JPanel buttonLayout = new JPanel(new FlowLayout());
// Sets Text //
converting.setText("Please wait while I convert your files");
// disables button //
OK.setEnabled(false);
OK.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});
// adds to the layouts //
textLayout.add(converting);
buttonLayout.add(OK);
mainLayout.add(textLayout, BorderLayout.CENTER);
mainLayout.add(buttonLayout, BorderLayout.SOUTH);
// adds to the frame //
contentPane.add(mainLayout);
}
public void convert(){
count = 0;
for (int i = 0; i <10; i++){
System.out.println("Copy "+i);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
}
count++;
}
alert();
}
public void alert(){
OK.setEnabled(true);
// String total = String.valueOf(Convert.result());
converting.setText("Sucsess! " + count + " files Converted");
}
}